Wear-resistant, polycrystalline diamond compacts (“PDCs”) are utilized in a variety of mechanical applications. For example, PDCs are used in drilling tools (e.g., cutting elements, gage trimmers, etc.), machining equipment, bearing apparatuses, wire-drawing machinery, and in other mechanical apparatuses.
PDCs have found particular utility as superabrasive cutting elements in rotary drill bits, such as roller cone drill bits and fixed cutter drill bits. A PDC cutting element typically includes a superabrasive polycrystalline diamond (“PCD”) layer commonly known as a polycrystalline diamond or PCD table. The PCD table is formed and bonded to a substrate using a high-pressure/high-temperature (“HPHT”) process. The PDC cutting element may be brazed directly into a preformed pocket, socket, or other receptacle formed in a bit body. The substrate may often be brazed or otherwise joined to an attachment member, such as a cylindrical backing. A rotary drill bit typically includes a number of PDC cutting elements affixed to the bit body. It is also known that a stud carrying the PDC may be used as a PDC cutting element when mounted to a bit body of a rotary drill bit by press-fitting, brazing, or otherwise securing the stud into a receptacle formed in the bit body.
Conventional PDCs are normally fabricated by placing a layer of diamond particles adjacent to a surface of a cemented carbide substrate and into a canister assembly. The canister assembly including the cemented carbide substrate and layer of diamond particles therein may be surrounded by various different pressure transmitting media (e.g., salt liners), positioned in a graphite tube having graphite end caps disposed at respective ends of the graphite tube that forms a heater assembly, and finally embedded in a cube-shaped gasket medium (e.g., pyrophyllite). In an HPHT process used to form a PDC, anvils of an ultra-high pressure cubic press apply pressure to the cube-shaped gasket medium and the contents therein, while the cemented carbide substrate and layer of diamond particles are controllably heated to a selected temperature at which sintering of the diamond particles is effected by passing a current through the graphite tube and end caps.